It is proposed to develop a panel of monoclonal antibodies to human parainfluenza virus types 1 and 2. Antibodies will be evaluated by neutralization, hemmagglutination inhibiition, neuraminidase inhibition, fusion inhibition, ELISA, immune precipitation, Western blot, and immunofluorescence assays. The objective of the Phase I proposal is to identify monoclonal antibodies specific for the surface glycoproteins (HN and F) of these viruses, as well as to other major virion polypeptides. The long term objective is to utilize such antibodies for development of improved vaccines and rapid diagnostic tests.